SwePub
Sök i SwePub databas

  Extended search

Träfflista för sökning "WFRF:(Johnson David C) ;hsvcat:4"

Search: WFRF:(Johnson David C) > Agricultural Sciences

  • Result 1-8 of 8
Sort/group result
   
EnumerationReferenceCoverFind
1.
  • Davies, Stuart J., et al. (author)
  • ForestGEO: Understanding forest diversity and dynamics through a global observatory network
  • 2021
  • In: Biological Conservation. - : Elsevier BV. - 0006-3207. ; 253
  • Journal article (peer-reviewed)abstract
    • ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimensions, censusing of all stems ≥1 cm in diameter, inclusion of tropical, temperate and boreal forests, and investigation of additional biotic (e.g., arthropods) and abiotic (e.g., soils) drivers, which together provide a holistic view of forest functioning. The 71 FDPs in 27 countries include approximately 7.33 million living trees and about 12,000 species, representing 20% of the world's known tree diversity. With >1300 published papers, ForestGEO researchers have made significant contributions in two fundamental areas: species coexistence and diversity, and ecosystem functioning. Specifically, defining the major biotic and abiotic controls on the distribution and coexistence of species and functional types and on variation in species' demography has led to improved understanding of how the multiple dimensions of forest diversity are structured across space and time and how this diversity relates to the processes controlling the role of forests in the Earth system. Nevertheless, knowledge gaps remain that impede our ability to predict how forest diversity and function will respond to climate change and other stressors. Meeting these global research challenges requires major advances in standardizing taxonomy of tropical species, resolving the main drivers of forest dynamics, and integrating plot-based ground and remote sensing observations to scale up estimates of forest diversity and function, coupled with improved predictive models. However, they cannot be met without greater financial commitment to sustain the long-term research of ForestGEO and other forest plot networks, greatly expanded scientific capacity across the world's forested nations, and increased collaboration and integration among research networks and disciplines addressing forest science.
  •  
2.
  • Short, Rebecca E., et al. (author)
  • Harnessing the diversity of small-scale actors is key to the future of aquatic food systems
  • 2021
  • In: Nature Food. - : Springer Science and Business Media LLC. - 2662-1355. ; 2:9, s. 733-741
  • Journal article (peer-reviewed)abstract
    • Small-scale fisheries and aquaculture (SSFA) provide livelihoods for over 100 million people and sustenance for -1 billion people, particularly in the Global South. Aquatic foods are distributed through diverse supply chains, with the potential to be highly adaptable to stresses and shocks, but face a growing range of threats and adaptive challenges. Contemporary governance assumes homogeneity in SSFA despite the diverse nature of this sector. Here we use SSFA actor profiles to capture the key dimensions and dynamism of SSFA diversity, reviewing contemporary threats and exploring opportunities for the SSFA sector. The heuristic framework can inform adaptive governance actions supporting the diversity and vital roles of SSFA in food systems, and in the health and livelihoods of nutritionally vulnerable people-supporting their viability through appropriate policies whilst fostering equitable and sustainable food systems.
  •  
3.
  • Bansal, Sheel, et al. (author)
  • Practical Guide to Measuring Wetland Carbon Pools and Fluxes
  • 2023
  • In: Wetlands (Wilmington, N.C.). - : SPRINGER. - 0277-5212 .- 1943-6246. ; 43:8
  • Research review (peer-reviewed)abstract
    • Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions.
  •  
4.
  • Callaghan, Terry, et al. (author)
  • Multi-Decadal Changes in Tundra Environments and Ecosystems : Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF)
  • 2011
  • In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 40:6, s. 705-716
  • Journal article (peer-reviewed)abstract
    • Understanding the responses of tundra systemsto global change has global implications. Most tundraregions lack sustained environmental monitoring and oneof the only ways to document multi-decadal change is toresample historic research sites. The International PolarYear (IPY) provided a unique opportunity for such researchthrough the Back to the Future (BTF) project (IPY project#512). This article synthesizes the results from 13 paperswithin this Ambio Special Issue. Abiotic changes includeglacial recession in the Altai Mountains, Russia; increasedsnow depth and hardness, permafrost warming, andincreased growing season length in sub-arctic Sweden;drying of ponds in Greenland; increased nutrient availabilityin Alaskan tundra ponds, and warming at mostlocations studied. Biotic changes ranged from relativelyminor plant community change at two sites in Greenland tomoderate change in the Yukon, and to dramatic increasesin shrub and tree density on Herschel Island, and in subarcticSweden. The population of geese tripled at one sitein northeast Greenland where biomass in non-grazed plotsdoubled. A model parameterized using results from a BTFstudy forecasts substantial declines in all snowbeds andincreases in shrub tundra on Niwot Ridge, Colorado overthe next century. In general, results support and provideimproved capacities for validating experimental manipulation,remote sensing, and modeling studies.
  •  
5.
  •  
6.
  • Jacquet, Jennifer, et al. (author)
  • Support US OCTOPUS Act to keep octopuses wild.
  • 2024
  • In: Science (New York, N.Y.). - 1095-9203. ; 385:6710, s. 721-722
  • Journal article (peer-reviewed)abstract
    • Commercial octopus farming is incapable of meeting welfare requirements, unsustainable, and unnecessary for sustenance. Although no commercial octopus farms currently exist, a Spanish seafood company plans to build one in the Canary Islands for Octopus vulgaris. In March, the US state of Washington banned octopus farming. Similar legislation has been introduced in California and Hawai‘i . Now, the federal government is proposing action. The US Congress should pass the OCTOPUS Act, a federal law that would prohibit commercial octopus aquaculture in the United States and the import of commercially farmed octopus or octopus products.
  •  
7.
  • Jiang, Mingkai, et al. (author)
  • The fate of carbon in a mature forest under carbon dioxide enrichment
  • 2020
  • In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 580:7802, s. 227-231
  • Journal article (peer-reviewed)abstract
    • Atmospheric carbon dioxide enrichment (eCO2) can enhance plant carbon uptake and growth1–5, thereby providing an important negative feedback to climate change by slowing the rate of increase of the atmospheric CO2 concentration6. Although evidence gathered from young aggrading forests has generally indicated a strong CO2 fertilization effect on biomass growth3–5, it is unclear whether mature forests respond to eCO2 in a similar way. In mature trees and forest stands7–10, photosynthetic uptake has been found to increase under eCO2 without any apparent accompanying growth response, leaving the fate of additional carbon fixed under eCO2 unclear4,5,7–11. Here using data from the first ecosystem-scale Free-Air CO2 Enrichment (FACE) experiment in a mature forest, we constructed a comprehensive ecosystem carbon budget to track the fate of carbon as the forest responded to four years of eCO2 exposure. We show that, although the eCO2 treatment of +150 parts per million (+38 per cent) above ambient levels induced a 12 per cent (+247 grams of carbon per square metre per year) increase in carbon uptake through gross primary production, this additional carbon uptake did not lead to increased carbon sequestration at the ecosystem level. Instead, the majority of the extra carbon was emitted back into the atmosphere via several respiratory fluxes, with increased soil respiration alone accounting for half of the total uptake surplus. Our results call into question the predominant thinking that the capacity of forests to act as carbon sinks will be generally enhanced under eCO2, and challenge the efficacy of climate mitigation strategies that rely on ubiquitous CO2 fertilization as a driver of increased carbon sinks in global forests.
  •  
8.
  • Leite, Melina de Souza, et al. (author)
  • Major axes of variation in tree demography across global forests
  • 2024
  • In: Ecography. - 0906-7590 .- 1600-0587.
  • Journal article (peer-reviewed)abstract
    • The future trajectory of global forests is closely intertwined with tree demography, and a major fundamental goal in ecology is to understand the key mechanisms governing spatio-temporal patterns in tree population dynamics. While previous research has made substantial progress in identifying the mechanisms individually, their relative importance among forests remains unclear mainly due to practical limitations. One approach to overcome these limitations is to group mechanisms according to their shared effects on the variability of tree vital rates and quantify patterns therein. We developed a conceptual and statistical framework (variance partitioning of Bayesian multilevel models) that attributes the variability in tree growth, mortality, and recruitment to variation in species, space, and time, and their interactions – categories we refer to as organising principles (OPs). We applied the framework to data from 21 forest plots covering more than 2.9 million trees of approximately 6500 species. We found that differences among species, the species OP, proved a major source of variability in tree vital rates, explaining 28–33% of demographic variance alone, and 14–17% in interaction with space, totalling 40–43%. Our results support the hypothesis that the range of vital rates is similar across global forests. However, the average variability among species declined with species richness, indicating that diverse forests featured smaller interspecific differences in vital rates. Moreover, decomposing the variance in vital rates into the proposed OPs showed the importance of unexplained variability, which includes individual variation, in tree demography. A focus on how demographic variance is organized in forests can facilitate the construction of more targeted models with clearer expectations of which covariates might drive a vital rate. This study therefore highlights the most promising avenues for future research, both in terms of understanding the relative contributions of groups of mechanisms to forest demography and diversity, and for improving projections of forest ecosystems.
  •  
Skapa referenser, mejla, bekava och länka
  • Result 1-8 of 8
Type of publication
journal article (6)
research review (1)
book chapter (1)
Type of content
peer-reviewed (7)
other academic/artistic (1)
Author/Editor
Malhi, Yadvinder (2)
Zuleta, Daniel, 1990 (2)
Davies, Stuart J. (2)
Olsson, Håkan (1)
Zhang, W. (1)
Wickland, Kimberly P ... (1)
show more...
Johnstone, Jill F. (1)
Keuper, Frida (1)
DelSontro, Tonya (1)
Gilbert, Gregory S. (1)
Hedenås, Henrik (1)
Bastviken, David (1)
Johansson, Margareta (1)
Emanuelsson, Urban (1)
Smith, Benjamin (1)
Zaehle, Sönke (1)
Åkerman, Jonas (1)
Eriksson, Håkan (1)
Andersson, Georg K S (1)
Creed, Irena F. (1)
Berg, Peter (1)
Carrillo, Yolima (1)
Castaneda-Gomez, Lau ... (1)
Reich, Peter B (1)
Luskin, Matthew S. (1)
Lin, David (1)
Uriarte, María (1)
Mangubhai, Sangeeta (1)
DeClerck, F. (1)
Failler, P. (1)
Arellano, Gabriel (1)
Niinemets, Ulo (1)
Arias-Ortiz, Ariane (1)
Tjoelker, Mark G (1)
Wallin, Marcus (1)
Christensen, Torben (1)
Liu, Yu (1)
Rinnan, Riikka (1)
Bergstrom, Carl T. (1)
Jacquet, Jennifer (1)
Bell, A. (1)
Bansal, Sheel (1)
Tangen, Brian A. (1)
Bridgham, Scott D. (1)
Desai, Ankur R. (1)
Krauss, Ken W. (1)
Neubauer, Scott C. (1)
Noe, Gregory B. (1)
Rosenberry, Donald O ... (1)
Trettin, Carl (1)
show less...
University
University of Gothenburg (3)
Lund University (3)
Swedish University of Agricultural Sciences (3)
Stockholm University (2)
Linköping University (2)
Kristianstad University College (1)
show more...
Uppsala University (1)
show less...
Language
English (8)
Research subject (UKÄ/SCB)
Natural sciences (7)
Social Sciences (1)

Year

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Close

Copy and save the link in order to return to this view